Kayaks are awesome for so many reasons. I live in central MS but marsh fishing is my thing. That said, I fish freshwater in my area somewhat regularly and then make a handful of yak trips a year to the MS coast or LA Marsh. There isn't really a wrong time of the year but in certain areas the tactics and specie will change with the season. The biggest advice I can give you is to demo kayaks and see what you like. Everything Kayak on the Coast and there is a big yak shop in Hattiesburg that does demo days also.